Breech construction for recoilless rifle



2 Sheets-Sheet 1 C W. MUSSER BREECH CONSTRUCTION FOR RECOILLESS RIFLE INVENTOR G WALTON MUSSER BY WaouMM, Ww- W Oct. 4, 1960 Filed April 10, 1958 Oct. 4, 1960 Filed April 10, 1958 C W. MUSSER BREECH CONSTRUCTION FOR RECOILLESS RIFLE 2 Sheets-Sheet 2 INVENTOR C WALTON MUSSER BREECH CONSTRUCTION FOR RECOILLESS RIFLE C Walton Musser, Beverly, Mass., assignor to the United States of America as represented by the Secretary of the Army Filed Apr. 10, 1958, Ser. No. 727,747

'3 Claims. (Cl. 891.7)

v (Granted under Title 35, US. Code (1952), see. 266) The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment of any royalty thereon.

This invention relates to recoilless rifles, and more particularly to an improved breech construction whereby the manufacture of such rifles is greatly simplified.

Recoilless rifles, as heretofore constructed, have had a breech construction such that considerable machine work of various kinds was involved in their manufacture. The breech construction of the present invention obviates much of this machine work in that it involves only three simple turning operations and a few minor milling operations. It consists mainly of a tube extending rearwardly of the rifle barrel, a cone or conical section located in the rear portion of the tube to form a venturi and three inserts interposed between the cone and the tube. This makes the tube or chamber a simple turning operation, the cone a simple turning operation and the inserts a simple turning operation with a few minor milling operations.

The invention will be better understood from the following description when considered in connection with the accompanying drawings and its scope is indicated by the appended claims.

Referring to the drawings:

Figs. 1A and 1B illustrate a preferred form of the invention,

Fig. 2 is an end view of the arrangement of Fig. 1,

Fig. 3 is a section taken on the line 33 of Fig. 2 illustrating how the various parts are assembled together, and

Fig. 4 illustrates a detail of a modified means for lockand releasing an element of the ammunition.

The rifle of Figs. 1A and 1B include a barrel to which is attached a rearwardly extending tube 11. Mounted within the rear portion of the tube 11 is a cone 12 which functions with the tube 11 to form a venturi for the escape of the gases generated by the firing of a projectile from the gun.

As shown more clearly in Fig. 2, three inserts 13, 14 and 15 are interposed between the tube 11 and the cone 12. These inserts are locked to the interior of the tube 11 by a series of modified Woodruff keys 16, 17, 18, 19 and 20. These keys are circular on two sides instead of only one side. Similar keys 21, 22 and 23 are interposed between the conical centerpiece and the inserts. Additional Woodruff keys 24 are provided at right angles to these modified keys to aline the inserts properly at exactly 120 degrees apart.

For assembly purposes, the circular keyways cut into the cone are extended axially with the cone to where they run out of the conical surface. This extended portion is made of the order of .010 inch shallower in depth than the actual keyway itself so that the keys will snap into the keyways and lock the cone into place.

The inserts 13, 14- and 15 are made similar to the Cone dimensions on the inside but the outside is made States atent .025 inch larger in diameter than the inside of the tube 11 so that the tube will be distorted out of round." This is done to ensure that, during the firing of a maximum pressure round, the tube will never expand to a point where all this distortion is removed. Thus contact is maintained between the inserts and the tube at all times.

As shown more clearly in Figs. 3 and 4, a control member 25 is associated with means for locking the ammunition to the breech of the gun. This control member may assume various forms. In Fig. 3 it is shown as having a conical section arranged to engage an aperture in locking member 26 which is biased to its illustrated position by a spring 27. By pushing the member 25 inwardly, the spring 27 is compressed and the cartridge is released. In Fig. 4 the member 25 is shown as termimating in a lateral extension which is rotated in a circular opening in the lock 26 to compress the spring 27 and release the cartridge.

In the assembly of the gun of Fig. 10, (l) the keys 16 to 20 are force fitted into the keyways in the inner wall of the tube 11, (2) the inserts 13, 14 and 15 are force fitted onto these keys, (3) the keys 21 and 24 are force fitted into-the keyways on the inner surface of the inserts 13, 14 and 15, and (4) the cone 12 is passed through the muzzle of the barrel 10 and into engagement with the cone and the keys 21 to 24. As previously indicated, this operation leaves the tube 11 in a somewhat distorted condition so that a tight connection is always maintained between the various parts.

The gun illustrated by Figs. 1A and 1B is adapted to fire a projectile in the form of an unitary structure which is inserted through the muzzle of the gun and is locked into place by the latch 26. Thus a perforated casing 28 enclosing a propellant extends from the head of the pro jectile to a point somewhat to the rear of its fins where it is threaded onto a member 29. Supported by the member 29 is a member 30 having at one end a primer chamber and at the other of its ends a booster chamber which opens into a duct 31 extending through the boom of the projectile. Normally, the duct 31 is filled with quick burning powder and is provided with numerous openings between the quick burning powder and the propellant.

The present invention, however, is not limited to this particular type of gun but is readily adapted to use in connections with guns utilizing diiferent types of ammunition.

I claim:

1. The combination of a gun barrel, a tube extending rearwardly from said barrel to form a chamber adapted to receive gas for neutralizing the recoil incident to the firing of said gun, a cone within the rear portion of said tube, and support means extending between the inner wall of said tube and the outer wall of said cone to form a plurality of venturi openings, said support means including three inserts spaced apart by degrees, a plurality of modified Woodrufi keys force fitted between said inserts and said tube, and a plurality of modified Woodrulf keys force fitted between said inserts and said cone.

2. A combination according to claim 1 wherein a latch having an opening therethrough is spring biased to lock a round in said barrel, and a rod having a conical inner end is movable through an opening in one of said inserts in alinement with said opening to unlock said latch.

3. The combination of a gun barrel, a tube extending rearwardly from said barrel to form a chamber adapted to receive gas for neutralizing the recoil incident of the firing of said gun, a cone within the rear portion of said tube, and support means extending between the inner wall of said tube and the outer wall of said cone to form a plurality of venturi openings, said support including three inserts, a plurality of keys force fitted between said inserts and said tube, and a plurality of keys force fitted between said inserts and said cone, one of said keys between each of said inserts and said cone being at right angles to the remaining keys between said each insert and said cone, whereby said inserts are spaced apart by 120 degrees.

References Cited in the file of this patent UNITED STATES PATENTS Davis Nov. 23, 1948 Kroeger et a1. June 7, 1949 Fowler Dec. 27, 194-9 Kroeger et a1. Jan. 9, 1951 Hickman May 27', 1952 Musser May 14, 1957 

